纳米TiO2表面接枝聚苯乙烯及其抗紫外老化研究

利用偶联剂γ-甲基丙烯酰氧基丙基三甲氧基硅烷(KH570)对纳米TiO₂进行表面预处理, 在此基础上通过分散聚合工艺制备聚苯乙烯(PSt)接枝包覆纳米TiO₂. 运用红外光谱、热重分析及透射电镜对处理前后纳米TiO₂进行了表征, 并通过紫外人工加速老化试验比较了表面处理前后纳米TiO₂对聚丙烯/聚苯乙烯(PP/PSt)体系的抗紫外老化性能. 结果显示: KH570与纳米TiO₂表面羟基进行了缩合, PSt在粒子表面实现了接枝聚合, 接枝率约为60% (w); PSt接枝包覆纳米TiO₂呈均匀的微球形, 纳米TiO₂被包覆于微球内部; PSt接枝包覆后纳米TiO₂在PP/PSt中的分散效果较改性前有显著的改进, 其抗紫外老化性能明显优于改性前体系.

Study on Nano TiO2 Grafted with Polystyrene and Its Resistance to UV Aging

The TiO₂ nanoparticles were treated using coupling agent γ-(trimethoxysilyl)propyl methacrylate (KH570) and then grafted on its surface with polystyrene (PSt) by dispersion polymerization. The TiO₂ nanoparticles treated have been characterized by FTIR, thermal gravimetry analysis (TGA), transmission electron microscopy (TEM), and the resistance to UV aging of TiO₂ nanoparticles in polypropylene/polystyrene (PP/PSt) are compared by artificial accelerated UV aging testing. The results show that KH570 and PSt were grafted on the surface of TiO₂ nanoparticles and the grafting ratio of PSt is about 60% (w). The TiO₂ nanoparticles grafted with PSt appear even microsphere in which the TiO₂ nanoparticles are wrapped. The dispersion status of TiO₂ nanoparticles in PP/PSt has improved remarkably and the resistance to UV aging are enhanced greatly by grafting with PSt.